1. Field of the Invention
The present invention relates to a multi-decoder, which selectively switches a plurality of streams having mutually different coding to effect decoding, and to a coding method.
2. Description of the Related Art
In recent years, ground digital broadcasting has started, and thereby, broadcasting stations handle various compression coding video signals, such as MPEG2 (Moving Picture Experts Group 2), MPEG4 and M-JPEG.
Such broadcasting stations require confirmation of a broadcasting material stream by an operator. For this reason, a decoder for decoding the broadcasting material stream to the original video signal is needed. At the broadcasting station, various types of decoder, as well as a multi-decoder, which is capable of switching between various compression coding streams, are used to reproduce the broadcasting material stream.
In such an environment, the decoding delay between decoders differs. For this reason, when an input stream is switched, a video image is instantaneously stopped, and blackout occurs, which also leads to synchronization confusion.
Conventionally, there has been proposed a digital information recorder that smoothly realizes switching of stream between different coding techniques (e.g., Jpn. Pat. Appln. KOKAI Publication No. 2005-11453).
However, the foregoing recorder only manages the timing between coding techniques when the stream is coded, and does not switch between various compression coding streams when decoding them.